A file system filter driver can intercept requests targeted at a file system or another file system filter driver. By intercepting the request before it reaches its intended target, the filter driver can extend or replace functionality provided by the original target of the request. To develop file systems and file system filter drivers, you can use the Windows Driver Kit (WDK),which is provided by Microsoft.
Developing file system filter driver is certainly a challenge even with the resources available in the Windows Driver Kit (WDK). To simplify your development and to provide you with a robust and well-tested file system filter driver that works with all versions and patch releases of the Windows operating systems supported by Microsoft, EaseFilter Inc. offers the file system filter driver SDK which provides a complete, modular framework for building active file system filters in your application.